Chair for a body-sensible acoustic device

ABSTRACT

There is provided a lightweight chair for body-sensible acoustic device wherein each of the right and left sides of the chair is formed of a frame having a substantially parallelogram shape, and a front-leg arm and a rear-leg arm of each of the frames are arranged so that their tilt angles agree with that of the back portion of the chair. The back portion is pivotally mounted at the rear of upper side arms of the frames, and a seat portion is pivotally mounted at the upper portion of the front-leg arms. An electromechanical vibration transducer is affixed to the reverse side of the lumber portion of the chair so that the vibration direction becomes perpendicular to the back portion surface. Since the vibration direction of the transducer agrees with that of the frames, the frames do not interfere with the vibration of the chair, thereby enhancing the vibration efficiency.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a chair for a body-sensible acoustic device, the chair using a relatively lightweight chair as a base, and the chair providing an improved vibration efficiency and a high vibration effect by the reasonable vibration structure thereof.

[0003] 2. Description of the Related Art

[0004] Among chairs commercialized, there are chairs which have stateliness and a feeling of stability, ones which are light in weight and easily portable, and ones which provide ease of use. In addition, there are also chairs which are used in combination with a table or a desk. However, chairs which are each singly used will be treated here.

[0005] Chairs shown in FIGS. 5 to 10 have each features thereof. Specifically, the chair shown in FIGS. 5 and 6 is produced as a lightweight one wherein, in the right and left trapezoidal frames 1 thereof, support members 2 are laid across the center portions of the two front legs and across the upper portions of the two rear legs, wherein armrests 4 are mounted on upper side arms 3, and wherein a chair body 7 constituted of a seat portion 5 and a back portion 6 is fixed by bolts, with shaft portions 8 and 9 provided at the center portions of the two front legs and the upper portions of the two rear legs. Typically, the frames 1 are made of a rigid body such as an iron pipe, and the chair body 7 is formed of hard fabrics, urethane, or the like.

[0006] The chair shown in FIG. 7, which is similar to the above-described chair, is arranged so that the rear-leg arms 10 of the trapezoidal frames 1 at the side portions are tilted more forward, considering backward stability.

[0007] The chair shown in FIG. 8 is arranged so that an installation board 11 and side support portion 12 are securely fixed, and that the chair body 7 is supported by the side support portion 12. This chair has a structure in which prime importance is placed on the stability of the chair body 7, and which provides a feeling of security in a manner such that a user can sit in repose whatever posture a user may take with respect to the chair body 7. Here, the chair body 7 is supported by the shaft portion 13 provided between the seat portion 5 and the back portion 6, and the shaft portion 14 provided at the intermediate portion of the seat portion 5.

[0008] The chair shown in FIG. 9 is arranged so that the chair body 7 is fixed to, for example, a wooden frame body 15 having a rectangular shape. The chair 9 may be made as high-grade furnishing goods.

[0009] The chair shown in FIG. 10 is arranged that the chair body 7 is supported between a pair of U-type frames 16. This chair is light in weight, and structurally has cushioning property with respect to loads.

[0010] In this manner, chairs are intended for being sat on, and used for various applications depending on the comfort to sit on.

[0011] Meanwhile, movie theaters, game centers, or event halls are now provided with a screen or a display. Each of chairs provided before this screen or display is equipped with a vibration device which vibrates the chair in order to add sense of realism to scenery on the screen or display. This vibration device is arranged so as to cause a viewer to body-feel sounds by acoustically vibrating the chair depending on the scenery, thereby providing a stronger feeling of realism to the viewer.

[0012] As described above, however, chairs are produced placing primary importance on the comfort to sit on, and, of course, no consideration has nowadays been given to a vibration structure whereby a chair is vibrated to enhance sense of realism. When using a chair as a human body placing device with a view to obtaining body-sensible sounds, it is necessary to give consideration of the vibration structure required for the chair. With regard to the driving method for body-sensible vibration, however, electromechanical vibration transducers (hereinafter abbreviated as “Tr”) are proposed, and ones which are technically at a high level in detailed vibrations of sound and in the selection of vibration frequency region, are commercialized.

[0013] In actuality, however, even when attempting to mount the high-level transducer Tr onto a chair, a compromise must be made with the structure of chair which has a long history. Today it is a reality, therefore, that products which cannot sufficiently exert vibration efficiency or vibration effect are being produced.

[0014] The chairs shown in FIGS. 5 and 6 are produced as lightweight one, and hence, in that respect, the chair is apt to exert a high vibration efficiency. However, when the transducer Tr is affixed to the lower part of the back portion (lumbar portion 6 a) and vibration drive is performed, since the frames 1 have each a trapezoidal shape, the direction of the deflection of the frames becomes the direction indicated by the arrow B in FIG. 6, in contrast to the direction of the vibration indicated by the arrow A in the figure. That is, a disagreement occurs between the driving vector (arrow A direction) and the deflection vector (arrow B direction), resulting in a deteriorated vibration efficiency. Structurally, the frames 1 are vibrationally grounded to a floor m, and hence, the chair body 7 is difficult to vibrate without an element of deflection. If the frames 1 each take on a triangular structure, the rigidity thereof will be higher, and hence the element of deflection is more reduced, so that the chair can not vibrate although it has stability. Meanwhile, with regard to the installation position of the transducer Tr, it is known from practical experience that vibrating the back portion of a human body enhances a “sense of realism” effect by body feeling. Therefore, in the case of a chair also, such a portion is adopted as an installation position of the transducer Tr. Also, if the transducer Tr is affixed to the seat portion as shown in FIG. 6, a problem of feeling ticklish will occur. The above-described lower part of the back portion (lumbar portion 6 a) is the position from which the back portion 6 and the seat position 5 are balancedly driven without generating the above-mentioned problem.

[0015] As shown in FIG. 7, if each of the frames 1 takes on a structure such that the inner angles at continuous positions, formed between the upper side arm 3 and the rear-leg arm 10 of the frame 1 become large, the extending direction P of the arm in the vicinity of the shaft portion 9 will approach the vibration direction of the transducer Tr indicated by the arrow A, and the arm at this place will act so as to suppress the vibration, thereby making the back portion 6 difficult to vibrate. That is, when the angle formed between the tilting direction of the back portion 6 and the extending direction P of the arm in the vicinity of the shaft portion 9 approaches a right angle (90°), the arm resists the expansion and contraction of thereof because of a rigid body, thereby preventing the back portion 6 from vibrating.

[0016] In the chair shown in FIG. 7, when the inner angles of the arm portion straddling the shaft portion 9 are made large, this place becomes difficult to deflect in the direction of the arrow C in the figure but easy to deflect in the direction of the arrow B in the figure. As a consequent, the chair body 7 undesirably vibrates so as to float and sink, or, to move in the vertical direction. Furthermore, since the driving vector of the transducer Tr (arrow A direction) and the deflection vector of the frames 1 (arrow B direction) disagree, the loss increases. It is, therefore, desirable to make the driving vector of the transducer Tr and the deflection vector of the frames 1 agree with each other, thereby enhancing the efficiency.

[0017] The chair shown in FIG. 8 has high stability, but the supporting points (shaft portions 13 and 14) of the chair body 7 are eventually fixed on the floor m, and it can be said that the chair body 7 is also fixed on the floor m. Therefore, even if the transducer Tr is affixed to the lumber portion 6 a of the chair body 7, most of the vibration energy will expended in vibrating the floor m, and the vibration will not be much transmitted to a human body of interest, resulting in a deteriorated vibration efficiency. In order to vibrate the human body, the installation point of the transducer Tr must be vibrationally isolated. The chair shown in FIG. 8 is substantially grounded vibrationally, and in terms of electric equivalent circuit, it looks as if the transducer Tr were short-circuited to the ground. This chair shown in FIG. 8, therefore, is quite unsuited for a chair for obtaining a vibration effect.

[0018] The chair shown in FIG. 9 is arranged so that the frame body 15 is formed of robust legs, and that the supporting points (shaft portions 13 and 14) which support the frame body 7 are vibrationally close to the floor (grounding point). In this respect, therefore, the situation with regard to this chair becomes similar to that with regard to the chair shown in FIG. 8, incurring a deteriorated vibration efficiency. Even if the transducer Tr is affixed to the back portion 6, it will be difficult to transmit vibration to the seat portion 5 since the chair itself is robust.

[0019] It is easier to add vibration to the back portion 6 than to the seat portion 5. In this case, however, as indicated by an arrow D in the figure, the vibration mode in this case vibrates a head portion 6 b larger than the lumbar portion 6 a around the shaft portion 13. In order to obtain comfortable body-felt vibration, it is desirable to strongly vibrate the lumbar portion 6 a but not to transmit much vibration to the head portion 6 b (strongly vibrating the head portion 6 b causes discomfort). Since this vibration mode is contrary to the purpose of strongly vibrating the lumbar portion 6 a without transmitting much vibration to the head portion 6 b, the vibration effect is deteriorated.

[0020] The chair shown in FIG. 10 is arranged so that the U-type frames 16 thereof have cushioning performance in the direction of an arrow E in the figure, and that the seat portion 5 and the back portion 6 are vibrationally isolated from the floor m. This chair, therefore, has a high vibration efficiency, but if vibration is added after affixing the transducer Tr, the contact portions between the U-type frames 16 and the floor m come into an immobile state (supporting points). As a consequence, the shaft portion 9 vibrates larger than the shaft portion 8, and thereby the vibration mode is changed into one wherein the vibration amplitude of the head portion 6 b becomes larger than that of the lumbar portion 6 a, resulting in impairment of comfort. The driving vector of the transducer Tr is approximately the horizontal direction, whereas the deflection vector in the vicinity of the head portion 6 b becomes diagonally forward direction (45° direction) since the chair swings around S positions in FIG. 10 as supporting points, thereby generating disagreement between the driving vector and the deflection vector.

SUMMARY OF THE INVENTION

[0021] Accordingly, it is an object of the present invention to provide a chair for a body-sensible acoustic device which efficiently vibrates the chair to improve the vibration transmission to a user.

[0022] In order to achieve the above-described object, the present invention, in a first aspect, provides a chair for a body-sensible acoustic device. This chair comprises side portions which are provided at the right and left sides of the chair, and each of which is constituted of a frame having four sides, the frame being formed into a parallelogram shape wherein the front-leg arm and rear-leg arm of the chair are tilted backward; a back portion pivotally mounted to the rear portion of an upper side arm of each of the frames; a seat portion pivotally mounted to the upper portion of each of the front-leg arms; and an electromechanical vibration transducer affixed to the lower part on the reverse side of the back portion so that the vibration direction thereof is substantially perpendicular to the surface of the back portion. The backward tilt angle of the back portion being made substantially the same as the tilt angles of the front-leg arm and rear-leg arm of each of the frames.

[0023] In accordance with a second aspect of the present invention, there is provided a chair for a body-sensible acoustic device. This chair comprises side portions which are provided at the right and left sides of the chair, and each of which is constituted of a frame having four sides, the frame being formed into a parallelogram shape wherein the front-leg arm and rear-leg arm of the chair are tilted backward; a back portion pivotally mounted to the rear portion of an upper side arm of each of the frames; a seat portion pivotally mounted to the upper portion of each of the front-leg arms; and an electromechanical vibration transducer affixed to the rear-leg arm so that the vibration direction thereof is substantially perpendicular to the surface of the back portion. The backward tilt angle of the back portion being made substantially the same as the tilt angle of the front-leg arm and rear-leg arm of each of the frames.

[0024] The above and other objects, features, and advantages of the present invention will be clear from the following detailed description of the preferred embodiments of the invention in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0025]FIG. 1 is a side view illustrating a lightweight chair in accordance with an embodiment of the invention;

[0026]FIG. 2 is a perspective view illustrating the lightweight chair shown in FIG. 1;

[0027]FIG. 3 is a side view illustrating a lightweight chair in accordance with another embodiment of the invention;

[0028]FIG. 4 is a side view illustrating a chair in accordance with a still another embodiment of the invention;

[0029]FIG. 5 is a perspective view illustrating a conventional lightweight chair;

[0030]FIG. 6 is a side view illustrating the chair shown in FIG. 5;

[0031]FIG. 7 is a schematic view explaining the vibration effect of the chair shown in FIG. 6;

[0032]FIG. 8 is a schematic view illustrating a conventional heavyweight-type chair;

[0033]FIG. 9 is a schematic view illustrating a conventional stationary-type chair; and

[0034]FIG. 10 is a perspective view illustrating a conventional lightweight cushion-type chair.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0035] As shown in FIGS. 1 and 2, the chair for use with a body-sensible acoustic device 17 is arranged so that the framework thereof is constituted of a pair of parallelogram-shaped frames 1 which forms the side portions provided at the right and left sides of the chair, and support members 2 connecting the frames on the right and left sides. Between the pair of frames 1, there is provided a lightweight chair body 7 wherein a back portion 6 is pivotally mounted to the rear portion of an upper side arm 3 constituting each of the frames 1, and wherein a seat portion 5 is pivotally mounted to the upper portion of the front-leg arm 18 of each of the frames 1. A transducer Tr is affixed to the reverse side of the lower portion of the back portion (lumbar portion 6 a).

[0036] The rear-leg arm 10 of each of the frames 1 is arranged so that the tilt angle thereof agrees with that of the back portion 6, and the back portion 6 is disposed in parallel to the front-leg arm 18 and the rear-leg arm 10. Bottom arm portions 19 are worked into a stable shape with respect to the floor m. Also, a footrest 21 may be provided to the seat portion, and a second transducer Tr may be affixed to this footrest.

[0037] Next, the operation of the chair for a body-sensible acoustic device 17 will be described.

[0038] First, when vibrating the transducer Tr, the back portion 6 vibrates. The vibration direction of the transducer Tr is positioned so as to be perpendicular to the back portion 6 and fixed. Since the rear-leg arm 10 is formed so as to be substantially parallel to the back portion 6, the driving vector of the transducer Tr (arrow A direction) and the deflection vector of the frames 1 (arrow B direction) agree with each other. As a result, the frames 1 do not interfere with the vibration of the back portion 6 by the transducer Tr, thereby enhancing the vibration efficiency. Also, even though the lumbar portion 6 a vibrates, the head portion 6 b does not much vibrate, so that discomfort due to vibration is reduced. Furthermore, since the vibration efficiency is high, affixing a single transducer Tr will suffice for satisfactorily vibrating the seat portion 5.

[0039] Since the transducer Tr is affixed below the supporting point (pivot portion 9), the vibration mode in this case is improved over that in the chair shown in FIG. 10. That is, a desirable vibration wherein the lumbar portion 6 a is vibrated larger than the head portion 6 b, is obtained. In this manner, the reasonable vibration structure allows an improved vibration efficiency and a high vibration effect to be achieved. Thereby, a chair for a body-sensible acoustic device can be provided, the chair using a relatively lightweight chair shown in FIGS. 1 and 2 as a base, and the chair being suited to a body-sensible acoustic device.

[0040] Next, another embodiment of the present invention will be described with reference to FIG. 3.

[0041] This embodiment differs from the above-described chair for a body-sensible acoustic device 17 in the installation position of the transducer Tr, that is, the transducer Tr is affixed to the rear-leg arm 10 of a frame 1. By this installation method also, since the driving vector of the transducer Tr (arrow A direction) agrees with the deflection vector of the frames 1, the vibration becomes easy to be transmitted to the back portion 6, thereby increasing the vibration efficiency.

[0042] In addition, still another embodiment will be described with reference to FIG. 4.

[0043] This chair for a body-sensible acoustic device 17 is one which is constructed to legless chair specifications. Specifically, plane springs 20 are directly affixed below the seat portion 5, and these plane springs also serve as the upper side arm 3 of each of the frames 1. Herein, the plane springs 20 are adhered to the bottom arm 19. An armrest 4 is locked along the back portion 6, and is used as needed. These plane springs 20 allow the legless chair to efficiently vibrate, by their deflecting in the horizontal direction when the transducer Tr vibrates.

[0044] As is evident from the foregoing, in the first aspect of the present invention, the lightweight chair is constructed so that the front-leg arm and rear-leg arm of each of the frames with a substantially parallelogram shape is tilted backward, and that the tilt angle thereof is set in agreement with that of the back portion of the light weight chair. Therefore, when vibrating the electromechanical vibration transducer which is affixed to the lower portion on the reverse side of the back portion, the back portion of the lightweight chair vibrates, as well as the frames each having a substantially parallelogram shape can easily vibrate swingingly in a manner such that all arms are linked, and the frames do not interfere with the vibration of the back portion of the lightweight chair. This allows the lightweight chair to efficiently vibrate, thereby improving the vibration transmission to a user.

[0045] In the second aspect of the present invention, the electromechanical vibration transducer is affixed to the rear-leg arm of a frame with a substantially parallelogram shape. Therefore, when vibrating the electromechanical vibration transducer, the frames easily vibrate so as to vibrate the back portion in the direction perpendicular to the back portion, thereby efficiently vibrating the chair and improving the vibration transmission to a user.

[0046] While the present invention has been described with reference to what are at present considered to be the preferred embodiments, it is to be understood that various changes and modifications may be made thereto without departing from the invention in its broader aspects and therefore, it is intended that the appended claims cover all such changes and modifications that fall within the true spirit and scope of the invention. 

What is claimed is:
 1. A chair for a body-sensible acoustic device, said chair comprising: side portions which are provided at the right and left sides of said chair, and each of which is constituted of a frame having four sides; said frame being formed into a parallelogram shape wherein the front-leg arm and rear-leg arm of said chair are tilted backward; a back portion pivotally mounted to the rear portion of an upper side arm of each of said frames; a seat portion pivotally mounted to the upper portion of each of said front-leg arms; an electromechanical vibration transducer affixed to the lower part on the reverse side of the back portion so that the vibration direction thereof is substantially perpendicular to the surface of the back portion; and the backward tilt angle of said back portion being made substantially the same as the tilt angles of said front-leg arm and rear-leg arm of each of said frames.
 2. The chair for a body-sensible acoustic device, said chair comprising: side portions which are provided at the right and left sides of said chair, and each of which is constituted of a frame having four sides; said frame being formed into a parallelogram shape wherein the front-leg arm and rear-leg arm of said chair are tilted backward; a back portion pivotally mounted to the rear portion of an upper side arm of each of said frames; a seat portion pivotally mounted to the upper portion of each of said front-leg arms; the backward tilt angle of said back portion being made substantially the same as the tilt angles of said front-leg arm and rear-leg arm of each of said frames; and an electromechanical vibration transducer affixed to said rear-leg arm so that the vibration direction thereof is substantially perpendicular to the surface of the back portion. 